1. Field of the Invention
The present invention relates to the field of sharpening methods and apparatus in general and in particular to a universal jointing attachment for inserted tooth carbide heads.
2. Description of Related Art
As can be seen by reference to the following U.S. Pat. Nos. 993,367; 4,987,704; 4,581,856; and 4,512,114, the prior art is replete with myriad and diverse jointing arrangements for a variety of cutter heads used to produce different functions.
While all of the aforementioned prior art constructions are more than adequate for the basic purpose and function for which they have been specifically designed, they are uniformly deficient with respect to their failure to provide a simple, efficient, and practical universal jointing attachment for inserted tooth carbide heads in general and in particular for a specific type of thickness planer known in the industry as the Oliver xe2x80x9cSTRAITOPLANExe2x80x9d(trademark).
The aforementioned thickness planer is provided with a pair of cutter heads which come in either 24xe2x80x3, 30xe2x80x3 or 36xe2x80x3 wide wherein the upper cutter head is fixedly secured in the main or mill framework of the thickness planer and the bottom cutter head is disconnectable from the main drive motor of the mill and mounted on a carriage that can be laterally withdrawn relative to the mill.
At the present time, Oliver Manufacturing Company does not make a jointing attachment for their xe2x80x98STRAITOPLANExe2x80x9d(trademark) thickness planers, and users of that machine have encountered a great deal of difficulty in obtaining smooth cutting surfaces on the grinding knives provided thereon.
When grinding the individual knives, the allowable tolerances are between one and one and a half thousandths per inch and this process normally takes approximately 6 to 6xc2xd hours to complete. However, the individual knives can be jointed from 3 to 5 times between each grinding procedure.
It should also be noted that once the grinding wheel makes contact with the guide behind the knives, the knives have to be turned. Given the fact that each knife has four sides, each knife can be jointed 4 to 5 more times thereby extending the life of the knives; and, with almost 300 knives installed on one thickness planer at an average cost of $11 per knife, this represents very substantial savings.
As a consequence of the foregoing situation, there has existed a longstanding need among owners of Oliver xe2x80x9cSTRAITOPLANExe2x80x9d(trademark) thickness planers for a new and improved method and apparatus for jointing the inserted tooth carbide heads on both the upper and lower cutter heads of that device; and, the provision of such an arrangement is the stated objective of the present invention.
Briefly stated, the universal jointing attachment that forms the basis of the present invention comprises in general a bracket unit, a mounting unit, an auxiliary motor unit and a drive belt unit which cooperate with the existing structural components on the Oliver Manufacturing Co. xe2x80x9cSTRAITOPLANExe2x80x9d(trademark) thickness planers mentioned previously.
As will be explained in greater detail further on in the specification, the auxiliary motor unit is fixedly secured to the mounting unit which is pivotally connected to either an upper or a lower bracket unit which is affixed to a portion of the thickness planer and the drive belt unit suspends the auxiliary unit in a generally upright fashion relative to a selected one of the rotary cutter heads.
The motor unit is then actuated to impart counterclockwise rotation to the selected cutter head whose inserted tooth carbide heads are xe2x80x9cjointedxe2x80x9d by engagement with a grinding element that is laterally translatable relative to the selected cutter head.
In addition, the bracket unit and the mounting unit are specifically designed to allow for a 180xc2x0 rotation of the output shaft of the auxiliary motor unit relative to the thickness planer, as well as, for the lateral displacement of the auxiliary motor unit relative to both the selected cutter head and the thickness planer for the purpose of properly aligning the drive belt unit to impart counterclockwise rotation to the selected cutter head during the xe2x80x9cjointingxe2x80x9d process.